• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.
  • Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

Duplexer Suggestion

Status
Not open for further replies.

BlueDevil

Member
Premium Subscriber
Joined
May 5, 2010
Messages
715
Location
WA
#1
I am looking for suggestions for a duplexer to be used in a new VHF conventional analog system with a repeater TX frequency of 151.8950 and a repeater RX frequency of 159.9150. It will be in close proximity to an existing VHF conventional analog repeater operating on a repeater TX frequency of 155.1750 and repeater RX frequency of 153.7775. The existing repeater is a Motorola XPR8300 and transmits at 50watts and uses a Station Master Omnidirectional antenna with a Telewave 1554 bandpass duplexer.

I haven't purchased the repeater for the new system yet. It is licensed for 50watts and that's what I have been looking at. I am looking at a 2 element folded dipole antenna operating perpendicular or at 90 degrees from the Omnidirectional Station Master. Do I need a full bandpass/bandreject duplexer or would a bandpass/notch duplexer provide adequate isolation from the existing system?
 
Joined
Apr 11, 2008
Messages
411
Location
Tennessee
#4
Sinclair Q2223(?). 6 cavity ResLoc with notch capacitors.

FYI, XPR8300 repeater is only 25w max.

I will take a look at the Sinclar option.

I have to agree with kayn1n32008 -Sinclair's are amazing! My Elmer now uses Sinclair's on his machine, and as compared to other brands we see a positive difference using Sinclair.

Just my two cents and BlueDevil I wish you the best of luck with your VHF endeavors.
 
Joined
Jun 30, 2006
Messages
7,649
Location
So Cal - Richardson, TX - Tewksbury, MA
#5
Don't forget an isolator on the transmitter output before the duplexer. This will reduce the chance of your transmitters talking to each other and creating Intermod, plus it will protect your transmitter if the antenna or duplexer goes south.
prcguy
 
Joined
Dec 22, 2013
Messages
2,997
#7
I would certainly recommend a duplexer that employs bandpass characteristics on the receiver port. I encountered a repeater (45 MHz LOW BAND) that had spurious receiver responses 31 MHz below the operating frequency. The receiver was getting hammered by TX noise that was down at 14 MHz. The duplexer was a TX-RX pseudo bandpass and at the out of band spurious frequency there was virtually no rejection. A Sinclair BP duplexer did work. As far as RX band reject, you are going to have to somehow consider near by high power base stations as well as your own. And as others mentioned, the transmitter should have an isolator panel and tuned reject not only noise to its own RX, but keep other high power stations from entering. VHF is a mess.
 

BlueDevil

Member
Premium Subscriber
Joined
May 5, 2010
Messages
715
Location
WA
#9
Well the existing omnidirectional Station Master does a good job covering the area we need. The new repeater is only going to be needed to cover a specific area and needs to have a much larger beamwidth to cover the area that we need. I cannot vertically separate the antennas at all and can only offer minimal horizontal separation. So I figured I could at least orient them so the radiation patterns would have the least amount of interference. It probably doesn't matter that much but at least it's something...
 
Status
Not open for further replies.
Top